U.S. Pat. No. 4,314,648, issued Feb. 9, 1982, assigned to the assignee of this invention, and hereby incorporated by reference into this specification, discloses a gravity feed shelf for use in a display device which is not refrigerated and which is formed of a plurality of similarly constructed channel-like chutes assembled together on a display shelf.
U.S. Pat. No. 4,593,823, also assigned to the assignee of this invention, and likewise incorporated by reference into this specification, discloses a specially constructed gravity feed-type shelf unit arranged for disposition in spaced relation above another similarly constructed shelf unit, each unit comprising a gravity feed type main chute structure having side edges to which a supplementary chute structure is detachably mounted so as to render the device adaptable to accommodate various space requirements such as are to be found in refrigerated display cabinets commonly used in supermarkets, the shelf units being formed preferably by an injection molding procedure.
The above-identified inventions have been particularly suitable for gravity feeding of uniformly-shaped containers, such as 12-ounce soft drink cans. However, some soft drink bottlers have begun producing a contoured bottle containing 20 ounces of beverage. These contoured bottles do not have a uniform vertical cross-section, are taller than the soft drink cans they replace on the shelves, and have a higher center of gravity than the cylindrical cans. When one or more bottles are standing up in a feeding channel formed by two longitudinally extending, opposed, parallel side walls, the gravity feeding arrangement causes the bottle nearest the front wall to contact the usually U-shaped front wall of the channel. As a result of the bottle's contours and its height, this contact occurs only at the base of the front channel wall and since the front bottle is unsupported above the base and has a high center of gravity relative to the height of the front wall, the front bottles tend to tip or rotate over the front wall and fall out of the channels. Moreover, the floors of the channels are typically designed to reduce friction between the channel floors and the bottoms of the containers, which tends to increase the likelihood of tipping.
The prior art gravity-feed units continue to work well for cylindrical cans and other types of containers. Additionally, there are numerous such units in use at this time and it would be prohibitively expensive to purchase new shelving units which can accommodate the large contoured bottles without the bottles tipping out of their channels. Therefore, it would be desirable and economical to retain the existing units in use. However, because of the anticipated popularity of the new contoured bottles (which are often made of plastic in a form reminiscent of historic glass bottle designs), it would be desirable to store and display such bottles in these gravity-feed units without interfering with the user's ability to withdraw other types of containers, including the cylindrical cans, from the shelving units.